The present invention relates to photographic processing equipment, and specifically to an integrated system for complete photographic processing in a minimum space. The present invention incorporates the components of a standard darkroom, including a basin (processing sink), water system, processing chemical trays, wash bath, light table, safety light, drying screens and storage areas into a single integrated unit.
A standard photographic print is produced by exposing a sheet of paper coated with photosensitive chemicals, typically silver halide, to light projected through an image. Once a photographic image is recorded on the silver halide crystals of a sheet of print paper, typically by illuminating the print with a "negative" image projected through an enlarger, the chemicals on the print are processed to develop and "fix" the image onto the paper by treating the print with processing chemicals. After the print has been processed with three separate chemicals (developer, stop bath and fixer) the print is washed in water to remove any excess chemicals remaining on the print and dried.
In conventional photographic print development, these processing chemicals are found in shallow trays arrayed horizontally on a flat surface, typically a smooth countertop in a darkroom. These trays are normally arranged linearly, adjacent to each other on the countertop. A print being developed is first placed into the tray filled with developer, then transferred from the developer to the stop bath to the fixer to the wash area by manually carrying the print to and between the trays with a pair of tongs. Because each print is processed by "agitating" the print in a tray, moving it back and forth while completely submerged in the processing chemical to ensure thorough and uniform coverage, each tray has to be filled to a relatively great depth. This has the undesirable effect of wasting processing chemicals and precipitating accidental spillage.
During processing, each print is normally held vertically over a tray before transfer to the next tray to allow any excess chemical absorbed by the print or adhering to the surface to drip off the print. However, this frequently cannot be done when oversized prints (e.g., 20".times.24") are being developed because of the high probability of creasing the print while trying to raise it. In addition, for very large prints, it is simply not possible to raise the print high enough without assistance. These problems are particularly acute when archival prints are being developed because of the high porosity and absorptive properties of the fiber based paper used.
Another problem frequently encountered during traditional print processing in a photographic darkroom is that the prints tend to accumulate in a pile in the wash area where they are stacked directly on each other. This stacking prevents the water from adequately rinsing the chemicals off each print unless the water flows through the wash area under relatively high pressure. However, in addition to wasting water, high pressure water tends to fold and crease oversize prints without providing adequate rinsing and thus limits the number of oversize prints that can be efficiently developed.
Another problem encountered while processing oversized or archival prints is the tendency of these prints to fold or crease after the wash stage when the print is squeegeed. Using a conventional squeegee, it is extremely difficult to apply sufficient perpendicular compressive force while moving the squeegee in a straight line, and the squeegee is often skewed in the process, folding or creasing the print.
The traditional linear arrangement of development chemicals is particularly disadvantageous when developing oversized prints as the large trays needed to adequately cover the surface of each print can require a prohibitively large flat surface. If an adequately large surface is unavailable, a photographer may be forced to place the trays on the floor or somehow attempt to reuse a single large tray. Neither of these alternative procedures is regarded as satisfactory.
Another disadvantage of the traditional linear arrangement of print development chemicals is that when a photographer chooses to stop developing prints for a short period, oxidation and/or evaporation will quickly damage the chemicals unless the flow of air over the chemicals is reduced. Although this may be done by covering each of the individual trays used to develop standard size prints, it is impractical with the trays necessary for the development of oversized prints because of the large surface area which must be covered, ideally without any portion of the cover coming into contact with the chemical.
A photographer wishing to develop his or her own photographs has traditionally required a separate room that can be isolated from outside light and has a sink, a light table, a safe light, sufficient level countertop space to arrange the trays of development chemicals and wash bath, drying racks for the prints and storage space for the processing chemicals. These requirements cannot be met by an amateur photographer or a professional photographer without the resources for his or her own studio and darkroom. Furthermore, even a photographer with access to a typical darkroom with standard equipment is usually unable to develop prints larger than 11".times.14" because of the processing problems inherent in their large size.